package com.cn.wanxi.servlet;

import com.alibaba.fastjson.JSONObject;
import com.cn.wanxi.model.ResultModel;
import com.cn.wanxi.model.UploadModel;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import java.util.UUID;

@WebServlet("/upload")
public class UpLoadServlet extends HttpServlet {
    private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3;  // 3MB
    private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
    private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB
    // 上传文件存储目录
    private static final String UPLOAD_DIRECTORY = "/loadImg/";

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        resp.setCharacterEncoding("UTF-8");
        UploadModel uploadModel = new UploadModel();

//        要得到前端传递到后台的流（文件）


        // 检测是否为多媒体上传,理解成判断是否为文件上传
        if (!ServletFileUpload.isMultipartContent(req)) {
            return;
        }

        // 配置上传参数,临时文件存储
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中
        factory.setSizeThreshold(MEMORY_THRESHOLD);
        // 设置临时存储目录
        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

//        解析文件
        ServletFileUpload upload = new ServletFileUpload(factory);

        // 设置最大文件上传值
        upload.setFileSizeMax(MAX_FILE_SIZE);

        // 设置最大请求值 (包含文件和表单数据)
        upload.setSizeMax(MAX_REQUEST_SIZE);

        // 中文处理
        upload.setHeaderEncoding("UTF-8");

        // 构造临时路径来存储上传的文件
        // 这个路径相对当前应用的目录,需要将当前的文件保存到那个地方？
        String uploadPath = req.getServletContext().getRealPath("./") + File.separator + UPLOAD_DIRECTORY;
        System.out.println(uploadPath);
//        UUID 随机数 由32个随机字符串组合
//        String fileName = System.currentTimeMillis() + "-----" + "12.jpg";//前端传递到后台的文件名称
//        String path = uploadPath + fileName;

        // 如果目录不存在则创建
        File uploadDir = new File(uploadPath);
        if (!uploadDir.exists()) {
            uploadDir.mkdirs();
        }

        try {
            // 解析请求的内容提取文件数据
//            @SuppressWarnings("unchecked")//如果没有被选中则提示
            List<FileItem> formItems = upload.parseRequest(req);

            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据,
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段,
                    if (!item.isFormField()) {
                        String fileName = new File(item.getName()).getName();
                        fileName = System.currentTimeMillis() + "-----" + fileName;
                        String filePath = uploadPath + File.separator + fileName;
                        File storeFile = new File(filePath);
                        // 在控制台输出文件的上传路径
                        System.out.println(filePath);
                        // 保存文件到硬盘
                        item.write(storeFile);
                        uploadModel.setSrc(UPLOAD_DIRECTORY + fileName);
                        //        E:\wanxi\step-4\canyin04-0510\out\artifacts\canyin04_0510_war_exploded\\/loadImg
                        String webPath = uploadPath.split("/out/")[0];
                        File directory = new File(webPath + "/web/", UPLOAD_DIRECTORY);
                        if (!directory.exists()) {
                            directory.mkdirs();
                        }
                        File file = new File(directory, fileName);
                        item.write(file);
                    } else {
                        //如果上传过来包含普通表单数据,则在这里获取
//                        后面我们会拿username过来？权限问题
                    }
                }
            }
        } catch (Exception ex) {
            req.setAttribute("message",
                    "错误信息: " + ex.getMessage());
        }


        //必须传递一个前端需要的格式
//        JSONObject jsonObject = new JSONObject();
//        jsonObject.put("code", 0);
//        jsonObject.put("msg", "上传成功");
//        jsonObject.put("data", uploadModel);
//        resp.getWriter().println(jsonObject);
//        new ResultModel(0, "", uploadModel, 0);
        resp.getWriter().println(new ResultModel(0, "", uploadModel, 0));
    }
}
